Chris Ramsey's men produced a valiant performance against Arsenal on Wednesday but still suffered a 2-1 defeat at Loftus Road despite Charlie Austin's goal eight minutes from time.
That marked QPR's 17th league loss of the campaign and kept them three points adrift of safety.
"Of course, I'm looking forward to it," Sandro said. "But it won't be any easier. Arsenal and Spurs are much the same level. We played well in the first half against Arsenal, but they have two chances and score from both.
"We show we can play well against the top teams - but we cannot keep losing.
"We need a win to rebuild confidence in the changing room, and if we can score an early goal, we can win."
The encounter could also prove to be a pivotal moment in Tottenham's season, which they are keen to prevent from fizzling out following their 2-0 loss to Chelsea in the League Cup final last weekend.
"I had a great six months there at QPR," Townsend said. "They took a chance on me when no-one else would and I'm extremely grateful for that.
"It will be good to see the players, staff and fans who were great with me in my time there, and also Chris Ramsey, who I came through the Spurs system with from the Under-16s to the development squad and then the first team last season.
"I wish them all the luck from now until the end of the season and it will be good to see them - but of course we want the three points on Saturday."
